There is a big thread on AL Pots here somewhere that I read the other day. It covers all the speculation about issues with using AL pots. The key thing mentioned is that you want a layer of Aluminum Oxide built up on the pot. You don't want to scrub it off because it is going to separate your wort from the AL which could leach into the wort and produce undesired flavors. You can scrub your pot but if you remove the AL Oxide you will want to get it built back up. Just boil water in it for 30 min to 1 hr and it will be good to go.
The other thing mentioned was that you really don't need to go overboard cleaning it. Sanitizing it isn't needed because you are just going to boil the wort in there which will kill anything that might be in there. Obviously you want it clean but it doesn't need to be sterile.
In the thread, which was quite long, they said several times not to use Oxy clean that it would strip out the oxidization. I would think, like you mentioned, it would add to the oxidization but I am not a chemist and I haven't tried it. Worst case if it did strip out the oxidization just boil some water in it again and you are back to where you were when you started. While I plan to go to Keggles eventually, I am using a AL turkey kettle now. The only thing it has been used for other than beer is I steamed a bunch of corn in it this summer.
EDIT: Take a look at this thread... It is the one I mentioned reading above.